Introduction to Computational Linguistics

Dr. Radhika MamidiENG 270

Lecture 1

What is Linguistics?• The scientific study of human language

• Aim is to establish a theory by studying nature of a language and by applying this established theory to describe other languages

• Descriptive study not prescriptive

• Speech activity - speaker, hearer, setting, code, medium; plus topic, contextual knowledge, abiding social norms, communicative competence

Applied Linguistics

Subfields / Inter-disciplinary fields:

Sociolinguistics Lexicography Stylistics Computational

Linguistics Semiotics PsycholinguisticsLanguage Teaching/Learning Translation Studies Anthropological Linguistics

Note: Now ‘Applied Linguistics’ is associated with Lg teaching.

What is Computational linguistics?

Computational linguistics is an interdisciplinary field dealing with the statistical and logical modeling of natural language from a computational perspective.

Goal of Computational linguistics

• To make the computers understand human language.

• To use technology to build language tools.• Use computers to process or produce human

language.

We want to communicate with computers in the language we speak!

Why Computers should talk with us?

• The main obstacle in the interaction between human and computer is communication problem.

• Computers do not understand our language and learning computer language is difficult.

• Computer language do not match the structure of human thought.

• The use of human language in computer applications will benefit the user.

Most interesting CL application: chatbot

• A chatterbot (or chatbot) is a type of conversational agent.

• It is a computer program designed to simulate an intelligent conversation with one or more human users via auditory or textual methods.

• It is a computer program with artificial intelligence to talk to people through voices or typed words.

Computational Linguistics

Computer Science

Cognitive Science

Philosophy

Mathematics

Psychology

Linguistics

Computational linguistics is an interdisciplinary field. It takes input from different fields.

Relation of CL to Other Disciplines• Artificial Intelligence (notions of representation, search)

• Machine Learning (probabilistic or statistical techniques)

• Human Computer Interaction (HCI)

• Linguistics (Syntax, Semantics etc.)

• Information Retrieval

• Philosophy of language (formal logic)

• Electrical Engineering (Optical Character Recognition)

• Psychology (insight into learning of linguistic constructions)

Computational Linguisticsis closely related to…

• Natural Language Technology• Natural Language Engineering• Natural Language Processing• Artificial Intelligence

Some Applications of Computational Linguistics

• Spelling and Grammar Checkers • Screen readers for the blind• Machine readable Dictionaries• Machine Translation Systems• Question-Answering Systems• Information Retrieval• Information Extraction• Automatic Summarization

Example Application- Search Engine

Example Application- Spelling Checker

Example Application- Grammar Checker

Example Application- Question Answering

Example Application- Machine Translation

Assignment 1Due date: After 2 weeks

Write short essays [about 8-10 sentences] on the following topics:

• Spelling and grammar checkers• Your favorite search engine• You and a chatbot

You have to include examples, urls, references, sample data etc. wherever necessary. Don’t forget to add screenshots.

Marks will be deducted if any kind of plagiarism is found.